Well treatment apparatus and method

ABSTRACT

The current invention provides apparatus and methods for the downhole release of well treatment chemicals. In one aspect, the invention provides a method for the passive continuous release of well treatment chemicals. Another embodiment of the invention provides a method for selectively releasing well treatment chemicals. Further, the present invention provides a method for inhibiting scale formation in a production pipe string.

BACKGROUND OF THE INVENTION

[0001] Hydrocarbon production from a well is a complex and costlyoperation. To improve wellhead economics, modem production processes usea variety of well treatment chemicals to treat common problemsencountered during hydrocarbon production. Commonly encountered problemsinclude the production of scale producing compounds, wax buildup andcorrosion. To solve this wide variety of problems, the oil industry hasdeveloped several categories of well treatment chemicals. Anon-inclusive classification of well treatment chemicals includes: scaleinhibitors, biocides, corrosion inhibitors, hydrogen sulfide scavengers,well tracing materials and de-waxing agents.

[0002] Although well treatment chemicals resolve the specific problemencountered downhole, the treatment process does add additional costs towell operations. For example, a scale inhibiting treatment requires thecessation of production and injection of a scale inhibitor. Treatmentprocesses such as pumping, also known as the squeeze process, dumpbailing or other means of well intervention requires additionalpersonnel and use of specialized equipment not normally maintained atthe wellhead. For example, the squeeze process injects scale inhibitor,under pressure, into a producing formation. Subsequent oil productioncarries the scale inhibitor out of the formation with the producedfluid. The scale inhibitor alters the chemistry of the produced fluidprecluding precipitation of scale on the interior of the pipe string.

[0003] The lost production time associated with the squeeze process addsa significant financial burden to well operations. In a high productionwell, the loss of production for a single day generally representsseveral tens of thousands of dollars. For a low production well, thecosts associated with extra personnel, chemicals and equipment mayexceed the income generated by several months of production. Clearly,the ability to perform well treatment methods without interrupting welloperations will improve wellhead economics.

SUMMARY OF THE INVENTION

[0004] The current invention provides a method for delivering welltreatment chemicals to a downhole region of a wellbore. The method ofthe current invention places at least one well treatment chemical in atleast one well treatment device. The well treatment device isincorporated into a pipe string. Preferably, the interior of the welltreatment device is in fluid communication with the interior of the pipestring. The pipe string is positioned within a wellbore, whichpenetrates at least one subterranean formation. Following positioning ofthe pipe string, the well treatment chemicals are released.

[0005] The current invention also provides a method for controlling thedelivery of well treatment chemicals to a downhole region of a wellbore.The method places at least one well treatment chemical in at least onewell treatment device. The well treatment device is incorporated into apipe string. Subsequently, the pipe string is positioned within awellbore penetrating at least one subterranean formation. The welltreatment device has at least one valve selectively movable between anopen position and a closed position. When in the open position, thevalve permits fluid communication between the interior of the welltreatment device and the interior of the pipe string. The interior ofthe pipe string is also in fluid communication with the wellbore. Asfluid passes through the pipe string, the well operator controls therelease of the well treatment chemical by selectively opening andclosing the valve on the well treatment device.

[0006] The current invention also provides a downhole well treatmentsystem. The well treatment system comprises a pipe string or othersimilar structure. The pipe string includes at least one well treatmentdevice having at least one reservoir. Stored within the reservoir is atleast one chemical suitable for treating a downhole condition or thewellbore.

[0007] The downhole well treatment system may further comprise aselectively activated downhole well treatment system. In thisembodiment, the well treatment device has at least one valve selectivelymovable between a closed position and an open position. Placing thevalve in the open position provides fluid communication between thereservoir located within the treatment device and the interior of thepipe string. The interior of the pipe string is also in fluidcommunication with the wellbore.

[0008] Further, the present invention provides a method for inhibitingthe formation of scale on a pipe string or other downhole metalliccomponents. The method comprises placing at least one scale inhibitingchemical within at least one well treatment device. The well treatmentdevice is attached to a pipe string. Following loading of the welltreatment device with the scale inhibiting chemical, the pipe string ispositioned in a wellbore. Subsequently, the scale inhibiting chemical isreleased at a downhole region of the wellbore. Generally, the scaleinhibiting chemical is released during production of fluids from asubterranean formation penetrated by the wellbore.

[0009] Still further, the current invention provides a passive downholewell treatment system utilizing existing downhole devices. Anon-exclusive list of downhole devices useful in the current inventionmay include: side pocket mandrels, sand control screen devices, steeltubing, velocity tubing strings, siphon tubing strings, fiberglasstubing, tubings made of composite materials, dump bailing devices,plastic tubing or similar devices. As recognized by one skilled in theart, the listed devices contain void spaces or a reservoir or theequivalent thereof suitable for holding the desired materials.Additionally, these devices easily enable placement of the desiredmaterial in the fluid flow stream. Thus, the devices allow for the slowevolution of the desired materials into the produced fluids or gases.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a side cross-sectional view of one embodiment of thewell treatment device of the current invention.

[0011]FIG. 2 is a side cross-sectional view of another embodiment of thewell treatment device of the current invention.

[0012]FIG. 3 is a side cross-sectional view of a well treatment deviceof the current invention fitted with a valve on one end and a cap on theopposite end.

[0013]FIG. 4 is a side cross-sectional view of one embodiment of thecurrent invention where the well treatment device is located within aside pocket mandrel.

[0014]FIG. 5 is a bottom view of an embodiment of the current invention.

DETAILED DESCRIPTION OF THE INVENTION

[0015] I. The Well Treatment System

[0016] The present invention provides a well treatment system 115 fordelivering well treatment chemicals 120 to a downhole region. Welltreatment system 115 improves wellhead economics by delivering necessarywell treatment chemicals 120 without interrupting production operations.Well treatment system 115 includes a well treatment device 110 suitablefor incorporation into a conventional pipe string 118. The currentinvention is useful in all types of wells including but not limited tocased and uncased wells as well as vertical and directionally drilledwells. As used herein, the term “downhole region” includes thesubsurface portion of a wellbore 122, any subsurface production zonesand the hardware associated with operating the well.

[0017] The current invention will be described with reference to FIGS.1-5. FIG. 1 depicts wellbore 122 penetrating at least one subterraneanformation 150. A casing 123 is cemented in wellbore 122. Positionedwithin wellbore 122 is pipe string 118. Incorporated into pipe string118 is well treatment system 115. The method of incorporating andpositioning well treatment system 115 on or in pipe string 118 will bedetermined from well to well based on the intended use of well treatmentsystem 115. For example, well treatment system 115 may be attached tothe interior or exterior of pipe string 118 or may actually form part ofpipe string 118 as described below with reference to FIG. 4. The methodof attachment or incorporation is not critical to the current invention.

[0018] As shown in FIG. 1, a rod, pipe, tube or other similar structurehaving a passageway 112 extending from a first open end 114 to a secondopen end 116 provides the structure of well treatment device 110. Theconfiguration shown in FIG. 1 has the advantage of simplicity andavailability. Further, those skilled in the art of oil production caneasily attach well treatment devices 110 to pipe string 118. AlthoughFIG. 1 depicts a cylindrical member, such as a pipe, tube or conduit,the physical configuration of well treatment device 110 is not criticalto the current invention.

[0019] When incorporated into pipe string 118, well treatment device 110provides a means for delivering well treatment chemicals 120 to adownhole region of wellbore 122. As shown in FIG. 1, passageway 112provides a storage area for well treatment chemicals 120. Further, openends 114 and 116 of passageway 112 provide fluid communication betweenthe interior passageway 112 of well treatment device 110 and wellbore122. In this manner passageway 112 provides a reservoir 112 for storageof well treatment chemicals 120. Optionally, well treatment device 110may be permanently sealed at either end 114 or 116.

[0020]FIG. 1 depicts one preferred configuration of well treatmentsystem 115 with well treatment device 110 located on the interior ofpipe string 118. This configuration shields well treatment device 110from casing joints (not shown) and other downhole hazards that maydamage well treatment device 110 during positioning downhole. However,the functionality of well treatment device 110 does not depend upon thelocation and method of incorporating well treatment device 110 into pipestring 118. Rather, the current invention provides the well operatorwith the flexibility to incorporate well treatment device 110 as part ofpipe string 118 in any manner that provides fluid communication betweenreservoir 112, the interior of pipe string 118 and/or wellbore 122. Forexample, FIG. 1 depicts well treatment device 110 attached to the innerwall of a tubular device 108, which is connected to pipe string 118.Tubular device 108 may be any downhole apparatus including but notlimited to a filter, a perforated pipe or a liner.

[0021] In general, well treatment system 115 may utilize any componentincorporated into pipe string 118 having sufficient space to accommodatewell treatment device 110. For example, U.S. Pat. No. 5,934,376,incorporated herein by reference, provides an improved well completionapparatus in the form of a slotted liner having an internal sand screen.The apparatus described by the '376 patent has sufficient void space toaccommodate well treatment device 110. Therefore, well treatment 115system of the type described herein can be prepared by incorporatingwell treatment device 110 into the well completion device of the '376disclosure.

[0022] A non-exclusive list of pipe string 118 components suitable forforming well treatment system 115 would include: sand control screendevices, prepacked well filters, steel tubing, velocity tubing strings,coiled tubing, siphon tubing strings, fiberglass tubing, tubings made ofcomposite materials, dump bailing devices, sand control screens, plastictubing or similar devices. In general, the component of pipe string 118must provide a reservoir 112 for containing the desired well treatmentchemicals 120. Additionally, the well treatment device 110 must besuitable for placement in the flow stream thereby permitting fluidcontact with well treatment chemicals 120 and the evolution of desiredwell treatment chemicals 120 into the produced fluids or gases.

[0023] As previously noted, the physical configuration of well treatmentdevice 110 may vary depending on the application and manner ofincorporation within the pipe string 118. For example, an alternateembodiment of the well treatment device 110 of the current invention isidentified in FIG. 2 as 210, in connection with a well treatment system215. Well treatment device 210 comprises a channel attached to theexterior of pipe string 218; yet, well treatment device 210 provides thesame function as well treatment device 110. Well treatment device 210provides a reservoir 212 for well treatment chemicals 220. Further, openends 214 and 216 of well treatment device 210 permit fluid communicationbetween the reservoir 212 and wellbore 222. Further, if necessary toimprove fluid communication, perforations (not shown) may be cut ineither well treatment device 110 or 210.

[0024] In another aspect, the present invention provides well treatmentsystems 315 capable of regulating the release of well treatmentchemicals 320. As shown in FIG. 3, well treatment system 315 includesthe use of a well treatment device 310. Well treatment device 310comprises a passageway 312 between ends 314 and 316 and a valve 324 atend 314 and a sealing means such as a cap 326 or other suitable sealingmechanism at the opposing end 316. Valve 324 is movable between a closedposition and an open position. When in the open position, valve 324provides fluid communication between passageway 312 and the wellbore(not shown in FIG. 3). Thus, valve 324 provides the ability to regulatethe release of well treatment chemicals 320 from passageway 312.

[0025] Any valve suitable for use downhole will perform satisfactorilyin the current invention. A non-exclusive list of suitable valves wouldinclude: dynamic pressure variance activation, passive pressureactivation, temperature activated, electronically activated, seismicallyactivated, flow constituent activated, pH activated, sonicallyactivated, acoustically activated, and mechanically activated. Oneskilled in the art will be able to use valves of this nature and othersimilar valves in the practice of the current invention.

[0026] Preferably, the operator will manipulate valve 324 by means of anon-intervention mechanism such as pressure pulses, seismic signal orother similar signal. However, operational control of valve 324 may alsobe provided by any one of the following or similar type devices:mechanical activation device attached to slick line, electric wireline,coil tubing or other means to physically manipulate valve 324 to thedesired position. Upon activation, valve 324 opens thereby permittingpassing fluid to contact well treatment chemicals 320. Alternatively, asecond valve 324 can be substituted for cap 326.

[0027]FIG. 4 depicts yet another embodiment of well treatment system415. The system of FIG. 4 permits quick and easy replacement of spentwell treatment devices 410. The well treatment system 415 disclosed inFIG. 4 comprises a well treatment device 410 and a side pocket mandrel430 incorporated into a pipe string 418. When configured in this manner,well treatment system 415 permits retrieval and replacement of welltreatment devices 410 using currently available technology. For example,U.S. Pat. No. 5,797,453 (the '453 patent), incorporated herein byreference, demonstrates the retrieval of a gas lift valve from a sidepocket mandrel. As shown in the '453 disclosure, a latch carried by theupper end of the gas lift valve enables retrieval of the gas lift valveby a downhole tool. The technique taught by U.S. Pat. No. 5,797,453applies equally well to the retrieval of well treatment device 410fitted with a latch 432.

[0028] Thus, when configured as depicted in FIG. 4, the currentinvention provides an extremely flexible well treatment system 415. Thesystem shown in FIG. 4 uses a modified gas lift valve as well treatmentdevice 410. This embodiment of the current invention enables the welloperator to quickly substitute well treatment chemicals 420 in responseto a change in downhole conditions. Retrieval and replacement of welltreatment device 410 can be carried out by one skilled in the art usingcommon downhole tools as described in the '453 patent. As in thepreviously described well treatment systems 415, well treatment system415 includes a well treatment device 410 having a passageway 412 orreservoir 412. Located at end 416 of well treatment device 410 is latch432 and optionally located at the opposing end 414 is a valve 424

[0029]FIG. 5 depicts a bottom view of another embodiment of the currentinvention. As shown in FIG. 5, several well treatment devices 110 may bepositioned within pipe string 118. In this instance, well treatmentdevices 110 are located between a shroud 124 and wire wrap 126. In FIG.5, well treatment devices 110 are spaced at regular intervals withinpipe string 118; however, the current invention is not limited to aparticular spacing.

[0030] Additionally, FIG. 5 demonstrates the use of conventional pipestring 118 components to form well treatment device 110. For example,the structural elements 128 normally used to position wire wrap 126 awayfrom a perforated base pipe 130 may be hollow tubes. Perforated basepipe 130 includes perforations 132. These hollow areas allow structuralelements 128 to also operate as well treatment devices 110. Further, thecurrent invention contemplates combining wire wrap 126 and perforatedbase pipe 130 to form the components of well treatment device 110. Inthis arrangement, well treatment chemicals 120 are placed between wirewrap 126 and perforated base pipe 130 during pipe string 118 assembly.Thus, wire wrap 126 provides fluid communication between wellbore 122and well treatment chemicals 120. Likewise, perforated base pipe 130having perforations 132 provides fluid communication between theinterior of pipe string 118 and well treatment chemicals 120.Additionally, well treatment devices 110 may be positioned betweenshroud 124 and wire wrap 126.

[0031] Clearly the current invention contemplates several differentembodiments of well treatment system 115. The drawings and foregoingdiscussion are merely intended to describe the current embodiments andare not intended to limit the scope of the attached claims.

[0032] Well treatment chemicals 120 suitable for use in the currentinvention include any compound or group of compounds necessary to solveor prevent a downhole problem or a problem in a pipe string 118 or forany other desired purpose. For example, the following classes ofchemicals are commonly used in the downhole environment: scaleinhibitors, paraffin deposition inhibitors, viscosity breakers, gashydrate suppressors, emulsion breakers, oxygen scavengers, oxidizers,esters, corrosion inhibitors, hydrogen sulfide scavengers, biocides andashless dispersants. The inventors anticipate the continued developmentof additional chemicals to address downhole problems. Virtually any newclass of chemicals developed for downhole use and capable of beingstored in reservoir 112 or equivalent will be suitable for inclusion inthe current invention. Therefore, the above classifications merelyrepresent chemicals suitable for use in the current invention and do notlimit the invention in any manner.

[0033] II. Process for Chemically Treating a Well

[0034] With continued reference to the drawings, the followingdiscussion will describe the novel method for delivering well treatmentchemicals 120 to a downhole region of wellbore 122. The currentinventive method utilizes the well treatment systems described above.The actual configuration of the well treatment system 115 is notcritical to the current invention. Rather, the current invention merelyrequires that well treatment system 115 provide fluid communicationbetween the reservoir 112 of the well treatment device 110, the interiorof the pipe string 118 and/or wellbore 122. For conciseness, theremainder of this discussion will focus primarily on well treatmentsystem 115 incorporating well treatment device 110; however, theprocesses described herein apply equally well to the configurationsdepicted in FIGS. 2-5 and other embodiments of the current invention.

[0035] Based on a prior characterization of wellbore 122 and/orsubterranean formation 150, the well treatment device 110 is loaded withthe desired well treatment chemicals 120. The methods of this inventionare not limited to the use of a single class of chemicals. Provided thechemicals are compatible, multiple classes of chemicals may be loadedsimultaneously within reservoir 112. Alternatively, when well treatmentsystem 115 is configured as shown in FIG. 5, different well treatmentchemicals 120 may be spaced around pipe string 118 in separate welltreatment devices 110.

[0036] A non-limiting list of chemical classes suitable for use in thecurrent invention would include: scale inhibitors, paraffin depositioninhibitors, viscosity breakers, gas hydrate suppressors, emulsionbreakers, oxygen scavengers, oxidizers, esters, corrosion inhibitors,hydrogen sulfide scavengers, biocides, well tracers and ashlessdispersants. Additionally, the processes of the current invention shouldalso be suitable for downhole delivery of well treatment chemicals 120developed in the future.

[0037] The fitting of well treatment device 110 on pipe string 118normally follows the loading of the desired class of well treatmentchemicals 120 in well treatment device 110. The particular method forincorporating well treatment device 110 into pipe string 118 is notcritical to the current invention. In general, well treatment device 110can form part of pipe string 118 or other device located downhole.Alternatively, well treatment device 110 may be attached to a componentforming a part of pipe string 118 or other device located downhole.Further, as discussed above, existing components of pipe string 118 maybe adapted to function as well treatment device 110. For example, FIG.1, depicts well treatment device 110 attached to the inner wall oftubular device 108. Tubular device 108 may be any downhole apparatusincluding but not limited to a filter, a perforated pipe or a liner. Incontrast, FIG. 2 depicts well treatment device 110 as being attached tothe external portion of pipe spring 218. Additionally, FIG. 4 showsanother embodiment of the current invention wherein well treatmentdevice 410 is incorporated into side pocket mandrel 430. In allinstances, reservoir 112 or its equivalent is in fluid communicationwith wellbore 122 or is provided with the means, e.g. valve 424, topermit such fluid communication. The means of attachment to pipe string118 may be any procedure or configuration commonly used in constructionof pipe string 118 including but not limited to welding, threadedconnections, “clamped on,” “locking ring,” friction grip, or a custommating means. Finally, the process has been described with the step offilling reservoir 112 prior to placement of well treatment device 110 onthe pipe string 118. However, circumstances may dictate loadingreservoir 112 after incorporation of well treatment device 110 into pipestring 118.

[0038] Following incorporation of the well treatment device 110 intopipe string 118, pipe string 118 is positioned within wellbore 122according to techniques well known to those skilled in the art. The typeof wellbore 122 is not critical to the current invention. Wellbore 122may be cased or uncased. Additionally, the processes of the currentinvention will find equal application in both vertical and directionallydrilled wells. Further, the wells may be used for producing hydrocarbonsor for subterranean injection of fluids, solids or gases.

[0039] Once pipe string 118 has been positioned within wellbore 122,release of the well treatment chemicals 120 will occur when passingfluids enter reservoir 112 contacting well treatment chemicals 120 heldtherein. Therefore, the well treatment method of the current inventionworks equally well in both production and injection wells. In aninjection well, fluid injected downhole contacts well treatment device110 and well treatment chemicals 120 contained therein. The injectedfluid subsequently carries well treatment chemicals 120 intosubterranean formation 150.

[0040] When used in a production well, well treatment device 110releases well treatment chemicals 120 into the produced fluids. Once inthe produced fluid stream, well treatment chemicals 120 may either reactwith the produced fluid or may treat the surfaces of pipe string 118.

[0041] For example, produced fluids of many wells frequently form scaleon the interior of pipe string 118. The use of a scale inhibitingchemical treatment to counter this problem is well known as demonstratedby U.S. Pat. Nos. 6,173,780; 4,357,248; 4,393,938 and 5,002,126incorporated herein by reference. The current invention performs thescale inhibiting treatment without interrupting production operations.In the current invention, the method of precluding scale build up placesa scale inhibiting compound in reservoir 112 (or equivalent) of welltreatment device 110 (or equivalent). During production, produced fluidsenter pipe string 118 and contact well treatment chemicals 120 heldwithin reservoir 112 of well treatment device 110. In response tocontact by the produce fluids or operator control, well treatment device110 releases the scale inhibitor from reservoir 112. As the scaleinhibitor blends into the produced fluids, it reacts with the scalegenerating compounds or treats pipe string 118 precluding the formationof scale on pipe string 118 and other metal components located in thedownhole region. Thus, the current invention provides a process forsimultaneously inhibiting the formation of scale and producing fluidfrom subterranean formation 150.

[0042] In an alternative embodiment of the current method, the processof delivering well treatment chemicals 320 to a downhole region includesthe additional step of selectively releasing well treatment chemicals320 into the passing fluid stream. In this embodiment of the currentinvention, well treatment system 315 is prepared and installed asdescribed above. However, as shown in FIG. 3, well treatment system 315has been modified by the addition of at least one valve 324 to welltreatment device 310. When only one valve 324 is used, then the oppositeend 316 of well treatment device 310 is preferably sealed or capped.Valve 324 provides the means for regulating fluid communication betweenreservoir 312, the wellbore (not shown in FIG. 3) and/or the interior ofpipe string 318. Preferably, valve 324 is remotely activated from thesurface by means well known in the art. For example, valve 324 may becontrolled or activated by dynamic pressure variance activation, passivepressure activation, temperature activated, electronically activated,seismically activated or flow constituent activated. Activation of valve324 between the closed and open positions permits the controlled releaseof well treatment chemicals 320 into either the subterranean formation,not shown, or the produced fluids.

[0043] In the embodiment of the current invention depicted in FIG. 4,the process of the current invention includes the step of retrieving andreplacing well treatment device 410. In order to permit retrieval andreplacement of well treatment device 410, well treatment system 415 hasbeen modified by the addition of a means to permit subsequent retrievaland replacement of well treatment device 410. Preferably, well treatmentdevice 410 is fitted with a latch 432 similar or identical to thatcommonly used on gas lift valves 424 located within standard side pocketmandrels 430. However, any other mechanism suitable for engagement bytools used to retrieve other downhole devices should work equally wellin the process of the current invention. The ability to retrieve andreplace well treatment device 410 provides the well operator withincreased flexibility. In the event of a change in downhole conditionsor the chemistry of the produced fluids, the operator can replace welltreatment device 410 by use of standard tool retrieval techniques.Following retrieval, well treatment device 410, now loaded with theappropriate well treatment chemicals 420, can be placed downhole. Thisprocess also enables the replacement of spent well treatment devices410.

[0044] The methods of the current invention provide several advantagesover prior art methods. Of primary significance, the current inventionenables the production of fluid during the well treatment process.Additionally, the current invention may extend the treatment time bychoosing well treatment chemicals 420 for their ability to react withcompounds produced from subterranean formation, not shown, tosubsequently yield a desired well treatment compound. Alternatively, thewell treatment compounds can be formulated to release only at apredetermined downhole temperature, pressure or pH. Thus, well treatmentchemicals 120 remain in reservoir 112 or equivalent until the specificchange in downhole conditions takes place. Occurrence of the specifiedchange in downhole conditions triggers the release of the well treatmentchemicals 120 to counteract the undesired condition.

[0045] While the present invention has been described with reference toFIGS. 1-5, other embodiments of the current invention will be apparentto those skilled in the art. Thus, the foregoing specification isconsidered exemplary with the true scope and spirit of the inventionbeing indicated by the following claims.

What is claimed is:
 1. A method for delivering well treatment chemicalsto a downhole region of a wellbore comprising the steps of: placing atleast one well treatment chemical within a well treatment device;attaching the well treatment device to a pipe string; positioning thepipe string in the wellbore; releasing the well treatment chemicals. 2.The method of claim 1, wherein an interior of the treatment device is influid communication with the wellbore.
 3. The method of claim 2, whereinthe treatment device includes a valve moveable between an open and aclosed position, wherein the open position permits fluid communicationbetween the interior of the treatment device and the wellbore; and,wherein the step of releasing the well treatment chemicals is achievedby selectively opening the treatment device to permit fluidcommunication between the interior of the treatment device and thewellbore.
 4. The method of claim 3, wherein the treatment device isselectively opened by means selected from the group consisting ofdynamic pressure variance activation, passive pressure activation,temperature activation, electronic activation, seismic activation, flowconstituent activation, pH activation, sonic activation, acousticactivation, mechanical activation.
 5. The method of claim 1, includingthe additional step of retrieving and replacing the treatment device. 6.The method of claim 1, further comprising the step of contacting thewell treatment chemicals with a fluid passing through the pipe string,wherein the contact releases the well treatment chemicals.
 7. The methodof claim 1, wherein the treatment chemical is selected from the groupconsisting of scale inhibitors, paraffin deposition inhibitors,viscosity breakers, gas hydrate suppressor, emulsion breakers, oxygenscavengers, oxidizers, esters, corrosion inhibitors, hydrogen sulfidescavengers, biocides and ashless dispersants or mixtures thereof.
 8. Themethod of claim 6, wherein the contacting step comprises contact with aproduction fluid and the well treatment chemical chemically reacts withat least one component of the production fluid.
 9. The method of claim8, including the additional step of retrieving and replacing thetreatment device.
 10. The method of claim 1, wherein the treatmentchemical is released at a predetermined temperature, pressure or pH. 11.A method for the controlled delivery of at least one well treatmentchemical to a downhole region of a wellbore comprising the steps of:placing at least one well treatment chemical within at least one welltreatment device; attaching the well treatment device to a pipe string,the well treatment device having at least one valve, the valve beingmovable between a closed position and an open position, when placed inthe open position the valve permits fluid communication between theinterior of the well treatment device and the interior of the pipestring; positioning the pipe string in the wellbore; passing fluidthrough pipe string, and, selectively opening and closing the valve onthe well treatment device thereby controlling the release of the welltreatment chemical.
 12. The method of claim 11, comprising contactingthe well treatment chemical with the fluid passing through said pipestring thereby releasing the well treatment chemicals from the treatmentdevice.
 13. The method of claim 11, wherein the treatment device isselectively opened by means selected from the group consisting ofdynamic pressure variance activation, passive pressure activation,temperature activation, electronic activation, seismic activation, flowconstituent activation, pH activation, sonic activation, acousticactivation, mechanical activation.
 14. The method of claim 11, whereinthe treatment chemicals is selected from the group consisting of scaleinhibitors, paraffin deposition inhibitors, viscosity breakers, gashydrate suppressor, emulsion breakers, oxygen scavengers, oxidizers,esters, corrosion inhibitors, hydrogen sulfide scavengers, biocides andashless dispersants and mixtures thereof.
 15. The method of claim 11,wherein the well treatment chemical chemically reacts with at least oneproduced fluid from a formation penetrated by the wellbore.
 16. Themethod of claim 11, further comprising the step of releasing the welltreatment chemical in response to a change in wellbore temperature,wellbore pressure or pH of fluid located in the wellbore or anycombination thereof.
 17. The method of claim 11, including theadditional step of retrieving and replacing the treatment device.
 18. Adownhole well treatment system comprising: a pipe string; at least onewell treatment device carried by the pipe string; and, at least one welltreatment chemical located within the well treatment device.
 19. Thedownhole well treatment system of claim 18, wherein the well treatmentdevice has at least one valve, the valve having a closed position and anopen position and the interior of the treatment device is in fluidcommunication with the interior of the pipe string when the valve is inthe open position.
 20. The downhole well treatment system of claim 19,wherein the valve is selectively operable between the first and thesecond position.
 21. The downhole well treatment system of claim 18,wherein the treatment device is positioned within or on a pipe stringcomponent selected from the group consisting of a prepacked well filter,a slotted liner, coiled tubing, side pocket mandrel, sand control screendevices, steel tubing, velocity tubing strings, siphon tubing strings,fiberglass tubing, tubings made of composite materials, dump bailingdevices and plastic tubing.
 22. The downhole well treatment system ofclaim 18, wherein the well treatment chemical is selected from the groupconsisting of scale inhibitors, paraffin deposition inhibitors,viscosity breakers, gas hydrate suppressor, emulsion breakers, oxygenscavengers, oxidizers, esters, corrosion inhibitors, hydrogen sulfidescavengers, biocides and ashless dispersants and combinations thereof.23. The downhole well treatment system of claim 18, wherein the systemincludes a means for controlling the release of the well treatmentchemicals.
 24. The downhole well treatment system of claim 23, whereinthe means for controlling the release of the well treatment chemicals isselected from the group of dynamic pressure variance activated valves,passive pressure activated valves, temperature activated valves,electronically activated valves, seismically activated valves, flowconstituent activated valves, pH activated membranes, sonic activatedvalves, acoustically activated valves, mechanically activated valves.25. The downhole well treatment system of claim 18, wherein thetreatment device is fitted with at least one latch.
 26. A downhole welltreatment system comprising: a pipe string; at least one well treatmentdevice carried by the pipe string, the well treatment device having atleast one valve, the valve having a closed position and an openposition, the interior of the treatment device is in fluid communicationwith the interior of the pipe string when the valve is in the openposition; well treatment chemicals located within the well treatmentdevice; and, means for selectively operating the valve between theclosed and the open positions.
 27. The downhole well treatment system ofclaim 26, wherein the treatment device is fitted with at least onelatch.
 28. The downhole well treatment system of claim 26, wherein thewell treatment chemical is selected from the group consisting of scaleinhibitors, paraffin deposition inhibitors, viscosity breakers, gashydrate suppressor, emulsion breakers, oxygen scavengers, oxidizers,esters, corrosion inhibitors, hydrogen sulfide scavengers, biocides andashless dispersants and combinations thereof.
 29. The downhole welltreatment system of claim 26, wherein the well treatment device islocated on the exterior of the pipe string.
 30. The downhole welltreatment system of claim 26, wherein the well treatment device islocated on the interior of the pipe string.
 31. The downhole welltreatment system of claim 26, wherein the means for controlling therelease of the well treatment chemicals is selected from the group ofdynamic pressure variance activated valves, passive pressure activatedvalves, temperature activated valves, electronically activated valves,seismically activated valves, flow constituent activated valves, pHactivated membranes, sonic activated valves, acoustically activatedvalves, mechanically activated valves.
 32. A method inhibiting theformation of scale on downhole metallic components comprising the stepsof: placing at least one scale inhibiting chemical within at least onewell treatment device; attaching the well treatment device to a pipestring; positioning the pipe string in the wellbore; releasing the welltreatment chemicals.
 33. The method of claim 32, wherein the treatmentdevice includes a valve moveable between an open position and a closedposition, wherein the open position permits fluid communication betweenthe interior of the treatment device and the wellbore; and, wherein thestep of releasing the well treatment chemicals is achieved byselectively opening the treatment device to permit fluid communicationbetween the interior of the treatment device and the wellbore.
 34. Themethod of claim 31, including the additional step of retrieving andreplacing the treatment device.
 35. The method of claim 31, wherein thetreatment device is selectively opened by means selected from the groupconsisting of dynamic pressure variance activation, passive pressureactivation, temperature activation, electronic activation, seismicactivation, flow constituent activation, pH activation, sonicactivation, acoustic activation, mechanical activation.